var colors = ["Red", "Green", "White", "Black"];
var c1=""
var c2=""
var c3=""
colors.forEach(function (item,index){
    c1+=item;
    c2+=item;
    c3+=item;
    if (index<colors.length-1){
        c1+=" ";
        c3+=',';
        c2+='+';
    }

})
document.write(c1);document.write("<br>");
document.write(c2);document.write("<br>");
document.write(c3);